1. Field of the Invention
The present invention relates to the field of design and construction of an artificial offshore reef. More particularly the present invention relates to the field of design and construction of small scale artificial offshore reef to modify the ocean floor bottom for the sport of surfing.
2. Description of the Prior Art
Surfing is a popular sport. When a surfer rides a surfing wave, the force of the surfing wave makes him travel at a high sped on the peak of the surfing wave, which creates a great thrill.
It is pleasurable for a surfer to ride a perfect surfing wave. A surfing wave is formed when the bottom of a swell is slowed down by a certain configuration of the offshore ocean floor bottom, and the top of the swell topples over. The perfect surfing wave travels diagonally toward the shore and the top of the swell continuously topples over. Such a diagonally traveling surfing wave maintains not only a longitudinal hydrodynamic force aiming in a direction toward the shore, but also a transverse hydrodynamic force aiming in a direction along the shore. As the surfer rides the perfect surfing wave, he travels at a much greater speed since he is taking advantage of both hydrodynamic forces, and the combination of the two hydrodynamic forces is certainly greater than each individual one of the forces. In addition, within a limited distance perpendicular to the shore, the diagonally traveling surfing wave travels a longer passage, which gives the surfer a much longer ride.
However, the average waves found on most sandy beaches are imperfect for surfing. An imperfect surfing wave simply moves in a direction perpendicular to the shore and loops over along a single line parallel to the shore. It does not provide a surfer a continuously toppling wave, nor the opportunity to take the desirable riding angle. The reason that most sandy beaches do not provide the perfect surfing waves is that their near shore ocean floor bottoms do not have the desirable configuration that properly slows down the bottom of the swell and makes the swell move in a diagonal direction.
Unfortunately, as surfing is becoming a more and more popular sport, only a limited number of beaches have the desirable near shore ocean floor bottoms that provide perfect surfing waves, and these beaches are becoming more and more unbearably crowded. One way to solve this problem is to build offshore constructions to change the offshore ocean conditions of the average sandy beaches, so they can provide perfect surfing waves.
So far there has been no offshore construction ever designed and constructed for the purpose of surfing, although historically certain constructions have been built to modify the offshore ocean condition for other purposes. There are two major types of offshore constructions built to change the offshore ocean conditions: offshore jetties and underwater reefs, aiming at two different objectives. The offshore jetties have been built to modify the offshore ocean swell directions and patterns, whereas the artificial reefs have been built to modify the offshore ocean floor bottom.
The offshore jetties have been built for various purposes such as fishing, tidal power generation and beach erosion prevention. The option of constructing an offshore jetty for the sole purpose of surfing is practically unavailable, because such a large scale offshore jetty is simply not effective in modifying the directions and patterns of the near shore swell for the purpose of surfing. It is also not justifiable to construct an offshore jetty for the sole purpose of surfing because of its high cost of construction and its adverse effects on large scale beach environment.
Another option is to construct an artificial reef. Historically most artificial reefs have been built for the purpose of fishing. In recent years some artificial reefs have been built for the purpose of dissipating the energy of the swell to protect the near shore structures or prevent bach erosions. These traditional artificial reefs are usually designed with large scale linear configurations, and are constructed with very heavy and bulky materials such as large rocks or cast concrete forms. The construction of such artificial reefs involves very heavy equipment such as barges with the cranes, and is very costly. In addition, these traditional artificial reefs are permanently disposed.
It is obvious that these old fashioned methods of the artificial reef construction are not longer suitable for the construction of artificial reefs for purpose of surfing. For example, the artificial reefs designed for fishing enhancement are usually built far off the shore. If an artificial reef is to be built for the purpose of surfing, it has to be located very close to the shore such that the surfing waves generated by the reef are accessible for surfers. Using heavy equipment for transporting heavy and bulky materials at locations very close to the shore is both unsafe to the construction workers and harmful to the immediate environment of the nearby beach.
It will be desirable to design and construct a small scale artificial reef that is built with light and environmentally inert material and can be easily transported and installed at locations very close to the shore. The purpose of the artificial reef is to modify the offshore ocean floor bottom such that perfect surfing waves may be generated for the purpose of surfing, where the installation of the artificial reef contributes no harm to the immediate beach environment.